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(11) | EP 0 277 616 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method and device for removing bubbles from containers filled with a liquid |
| (57) A method for removing bubbles from a container made of synthetic resin or similar
material filled with liquid comprises a movement of inclination into at least one
direction applied to the container. The movement is performed gradually so that the
liquid will contact the whole surface of the inner wall of the container without any
shock from outside so to discharge bubbles adhering to the inner wall of the container
outside of the liquid and removing bubbles within the container completely. This is
performed with a system of rolls (5-9) and belts (10-13, 10a-13a) which contact the
container. |
[0002] The present invention relates to a method for removing bubbles adhering at an inner wall of a container made of synthetic resin or similar materials filled with a transparent or semitransparent liquid, which bubbles become an obstacle for inspecting if there exists any foreign substance in the container, and a device for performing said method.
[0003] A container such as an ampoule for injection, a glass bottle filled with a solution for transfusions etc. may contain foreign substances such as glass splinters, granular substances, fibers or the like. The existence of these foreign particles is a disadvantage by itself for quality. Accordingly, all containers filled with a solution for injection must receive an inspection so as to pick up the defective samples.
[0004] In Japanese Patents Nos. 1,123,819 and 1,123,830 and Japanese Patent laid-open application 57 (1982) - 142,252 is disclosed an optical automatic inspecting apparatus for detecting foreign substances contained in a container, by the following steps: rotating the container, such as an ampoule for injection, a bottle for transfusion etc., at high velocity, rapidly stopping the rotation, projecting a beam of light on the liquid in the container, receiving the beam of light passing through the liquid in the container by means of a light sensor; in case the amount of the received light is less than the predetermined amount, it is defined that foreign substances exist in the container.
[0005] However, in case of a filled container made of synthetic resin or similar material, there may exist bubbles on a surface of an inner wall of the container. It is possible that the known optical automatic inspecting device indicates a positive reaction by judging said bubbles as foreign substance.
[0006] In the container filled with solution, there is not only liquid but also gaseous phases such as air and/or nitrogen etc.; the volume of the container is determined with volumes of the liquid and gaseous phase. In a container made of synthetic resin, a number of small gaseous bubbles are easily created by vibration which the container receives in time of filling or during transportation of the container or during rotary movement the container. Further, the change of temperature of the container in various kinds of environments may cause bubbles. The gaseous bubbles adhere to the inner wall of the container, and they are hard to remove entirely from the inner wall of the container, even if the container settles for a long time after vibration, shock or the like.
[0007] When executing rotary movement at high velocity to the container by the same way as during the conventional optical automatic inspecting, the air existing in the upper portion of the container is received in the liquid to produce many further gaseous bubbles in the container. On the other hand, when performing only rotation at low velocity, the bubbles adhering at the inner wall of the container cannot be removed at all.
[0008] When the inspection for foreign substance is performed with the container carrying many small gaseous bubbles on its inner wall, the bubbles swimming in the liquid behave like foreign substances. Since the bubbles are hit by a light beam like foreign substances, it is probable that a container contains no foreign substances, but bubbles. Said container will be defined as having foreign substances.
[0009] It is an object of the present invention to provide a method and a device being extremely simple and economical to remove bubbles adhering at an inner wall of a container made of synthetic resin or similar material. There should not occur shocks which generate new bubbles in the container.
[0010] According to the present invention, this aim is achieved by a method which comprises movement of inclination in at least one direction applied to the container, so that the liquid will contact the surface of the whole inner wall of the container at relatively low velocity and without any shock from outside and so as to discharge bubbles adhering to the inner wall of the container outside of the liquid and removing bubbles within the container completely.
[0011] Performing the aforesaid method a device is proposed, which comprises a pair of right and left vertical rolls and a pair of upward and downward horizontal rolls arranged alternately, and belts provided between said pair of right and left vertical rolls, and said pair of upward and downward horizontal rolls adjoining each other, wherein the vertical roll on one side is linked with the horizontal roll on one side by one belt and the vertical roll on the other side is linked with the horizontal rolls on the other side by the other belt, and the two belts cross each other so as to apply an inclination in at least one direction to the container when holding the container.
[0012] The bubbles in the container are entirely removed by the method according to the mentioned invention. Since the inclination in a first and in a reverse direction of the container is performed by rolls and belts, the device may be produced at low costs. The rolls and the belts move smoothly, so no shock from the outside will occur. Where smoothly, so no shock from the outside will occur. Where it is difficult to remove bubbles due to the coefficient of viscosity of the liquid, removal of the bubbles may be achieved by adding a rotary movement of the container to the movement of the inclination. This may be performed by different velocities of rotation of the opposite rolls and by different velocities of movement of one belt contacting with one side of the container from that of the other belt contact with the other side of the container.
[0013] Further, the device according to the present invention may be applied to all containers made of synthetic resin or similar material of different shapes, like round type bottles and other containers having other shapes.
[0014] The drawings are showing:
Fig. 1 is a plane view on a device having stations or steps from A to G;
Fig. 2 is a front view on the device of Fig. 1;
Fig. 3 (a) is a view explaining conditions of a container from step B to step E;
Fig. 3 (b) is a view explaining conditions of rotation of the container in each step of Fig. 3 (a);
Figs. 4 and 5 are views explaining conditions of the container moved by belts;
Figs. 6 and 7 are a plane view and a front view showing the site in which rolls 15 are put to the round belts;
Fig. 8 is a front view of a vertical roll and a horizontal roll;
Fig. 9 is a front view showing one embodiment of the roll 15.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In Figs. 1 to 5, a first embodiment of a device for removing bubbles from a container made of synthetic resin filled with liquid according to the present is shown. The embodiment first will be explained on Fig. 1 and Fig. 2. A conveyor belt 1 has a first part with which steps from A to F are performed. Another part of the conveyor belt will perform step G. Turn tables 2, 3, 4 are provided at parts where the moving direction of a container is changed.
[0016] At steps or stations from B to E, series of a pair of right and left vertical rolls (5, 5a), (6, 6a) and (7, 7a) are provided. Series of a pair of upward and downward horizontal rolls (8, 8a) and (9, 9a) are arranged between each pair of the vertical rolls. The shapes of the vertical rolls and horizontal rolls are to be seen from Fig. 8.
[0017] An inclination and a return movement is forced upon the container by steps A, B, C, D, E, F and G as follows:
Step A:
[0018] A container conveyed continously from a sterilizing station is supplied to a device for removing bubbles. At this point, many small gas bubbles may adhere to the inner wall of a polyethylene cotainer.
Step B:
[0019] A container is conveyed from step A in upward position. At step B an inclination is forced upon the container, so that it will turn or topple to the right side.
Step C:
[0020] Further rotary movement is forced upon the container conveyed from step B in right-sideways inclination, so as to turn the container downward.
Step D:
[0021] A further inclination is gradually forced upon the container conveyed from step C in lying position so as to turn to the left side.
Step E:
[0022] Further rotation is forced upon the container conveyed from step D in left-side inclined position so as to turn upward into the same position as step A.
Step F:
Step G.
[0026] In step B the container is gradually inclined to the right side. In step C the position of the container is gradually changed from a right inclination to a upside-down vertical position. In step D the position of the container is gradually inclined from vertical position to the left side. In step E the position of the container is gradually changed from the left side to an upward right position.
[0027] A device or apparatus for performing steps B to E is described according to Figs. 4 and 5. Fig. 4 shows steps from B to C, and Fig. 5 shows steps from D to E.
1. Step B is performed between vertical rolls 5, 5a and horizontal rolls 8, 8a. Several endless roiund belts 10 are linking the vertical roll 5 and the horizontal roll 8, respectively, and several further endless round belts 10a link the vertical roll 5a positioned on left side of the vertical roll 5 and the horizontal roll 8a positioned below the horizontal roll 8, respectively. Further each group of belts cross each other. The container is held by the inner side of the round belts 10, 10a, linking the vertical rolls 5, 5a and horizontal rolls 8, 8a. Said container is gradually moved and inclined to the right.
2. Step C is performed between the vertical rolls 8, 8a and the horizontal rolls 6, 6a. Namely, several endless horizontal roll 8, respectively, and several endless round belts 11a link the vertical roll 6 provided at the right side of the vertical roll 6a and the horizontal roll 8a, respectively. The container is held by the inner side of round belt 11, 11a linking the vertical rolls 6, 6a and the horizontal roll 8, 8a. Said container is gradually moved and turned downward.
3. Step B is performed between the vertical rolls 6, 6a and the horizontal rolls 9, 9a. Namely, several endless round belts 12 link the vertical roll 6 and the horizontal roll 9, respectively. Further, the endless round belt 12a links the vertical roll 6a and the horizontal roll 9a provided below the horizontal roll 9, respectively. The container is held by the inner side of the round belts 12, 12a linking the vertical rolls 6, 6a and the horizontal rolls 9, 9a. Said container is gradually moved and turned to the left side.
4. Step E is performed between the vertical rolls 7, 7a and the horizontal rolls 9, 9a. Namely, endless round belts 13 link the vertical roll 7 and the horizontal roll 9a, respectively. Further endless round belts 13a link the vertical roll 7a and the horizontal roll 9. The container is held by the belts 13, 13a linking the vertical rolls 7, 7a and horizontal rolls 9, 9a, said container is gradually moved and turned upward.
5. Motors 14, 14a are provided for the vertical rolls 7, 7a as described in Fig. 1 and 2. The shafts of the motors 14, 14a are connected with the vertical rolls 7, 7a. When rotary movement according to the arrow is applied to the vertical roll 7 as described in Fig. 7,, the rotary movement also is applied to the round belt 13a, the round belt 12a, the round belt 11, and the round belt 10.
[0028] On the other hand, when rotary movement according to the arrow is applied to the vertical roll 7a as described in Fig. 7, the rotary movement thereof is also applied to the round belt 13, the round belt 12, the round belt 11a, and the round belt 10a. The vertical rolls 5, 5a and the vertical rolls 6, 6a rotate according to the direction of the arrow in Fig. 7, and the horizontal rolls 8, 8a and horizontal rolls 9, 9a rotate to the direction of the arrow in Fig. 6. In the shown steps B to F, the belt conveyor 1 itself does not convey the containers.
[0029] Another embodiment is disclosed in Fig. 6 and 7. A roll 15 for adding tension to the round belt is arranged between the round belt 10, 10a, respectively. A example of the roll 15 is shown in Fig. 9. The roll 15 has many grooves 16 for holding the round belts. The round belt contacting the container is laid into the outside groove 16ʹ. A bar 17 is installed horizontally on the left side of the upper portion of a pillar 20. The roll 15 is hanged down from the bar 17 by means of a pair of a right and a left pin 18. The pins 18 are provided with springs, so that the roll 15 may incline to a certain degree. The bar 17 itself may change the angel of its inclination.
[0030] Vertical rolls 19 are arranged which prevent that said round belts from contacting each other, when they transport the container. The belts are kept between said vertical rolls 19.
[0031] In the present invention, a passage is provided for conveying the container held by the round belts linking a pair of right and left vertical rolls, a pair of upward and downward horizontal rolls and the horizontal roll and the vertical roll.
[0032] In the embodiment shown in Fig. 4 and 5, the container is turned 360 degrees during conveying. However, by changing the combination of the round belts lying around the vertical rolls and the horizontal rolls, the present invention can be changed for many other kinds of application. For example, it is possible to incline the container only to the right or to left direction. During transportation the container may rotate 180 degrees; then putting it back to the original position,or the container may rotate for several predetermined times.
[0033] With the above mentioned steps, bubbles in the container filled with liquid are substantially removed. If it is difficult to remove the bubbles, e.g., due to the coefficient of viscosity of the solution, removal of the bubbles may be achieved by adding a rotary movement of the container to the movement of inclination. This is performed by different velocities of rotation of the vertical roll and the horizontal roll, and then changing the velocity of movement of one round belt contacting with one side of the container from that of the other round belt contacting the other side of the container.
[0035] The surface of the liquid may be contacted with the whole round area of the inner wall of the container by using the container according to the present invention. Therefore, the bubbles adhering to the inner wall of the container will be removed completely by inclination of the reverse movement of the container. Further, the movement of inclination as the reverse movement of the container may be performed smoothly without any shock. The device itself is of economical construction. The aforementioned disadvantages may be dispelled.